Gonadal defects in Cited2 -mutant mice indicate a role for SF1 in both testis and ovary differentiation
Original Article | Published: 24 July 2009
Alexander N. Combes1, Cassy M. Spiller1, Vincent R. Harley2, Andrew H. Sinclair3, Sally L. Dunwoodie4,5, Dagmar Wilhelm1 and Peter Koopman*,1
1Division of Molecular Genetics and Development, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 2Prince Henry’s Institute of Medical Research, Melbourne, VIC, 3Murdoch Children’s Research Institute, and Dept. of Paediatrics, University of Melbourne, Royal Children’s Hospital, Melbourne, VIC, 4Developmental Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, Sydney, NSW and 5Faculty of Medicine, University of New South Wales, Kensington, Sydney, NSW, Australia
Sex determination is regulated by a molecular antagonism between testis- and ovary-determining pathways in the supporting cell lineage of the gonadal primordia. Genes important for maintaining this lineage play critical roles in early gonadal development, but their influence on testis and ovary differentiation is unclear due to the severity of loss-of-function phenotypes. The transcription factor SF1 (Nr5a1/Ad4BP) is one such factor, required for establishing the supporting cell lineage, and for propagating the male pathway. In the gonad, Sf1 expression is enhanced by the transcriptional co-factor Cited2. We have used the reduced levels of Sf1 expression in Cited2 -/- mice as a hypomorphic model to gain insight into the sex-specific roles of SF1 function in gonadal development. In XY mutant mice, we found that testis development was delayed in Cited2 -/- gonads, and that testis structure was permanently disrupted. In XX Cited2 -/- gonads, ectopic cell migration was observed which correlated with a transient upregulation of Fgf9, and a delay in Wnt4 then Foxl2 expression. These data suggest a novel role for SF1 in promoting ovarian development in addition to its roles in testis differentiation.